That is the "LOAD" error code.
However, to service the C:31 code, Sony recommends you do the following:
- Turn off the camcorder.
- Remove the battery or disconnect the AC power adapter for 60 seconds.
- Insert the battery or reconnect the AC adapter.
- Turn on the camcorder.
- If the error message appears, service may be required.
If your camcorder still shows the same error code, then you'll have to send in your camcorder for service.